http://illuminations.nctm.org/Lesson.aspx?id=2523 “The Stomachion is an ancient tangram-type puzzle. Believed by some to have been created by Archimedes, it consists of 14 pieces cut from a square. The pieces can be rearranged to form other interesting shapes. In this lesson, students learn about the history of the Stomachion, use the pieces to create other figures, learn about …